Food For Thought: The Subtle Forces That Affect Your Appetite | KUOW News and Information

Food For Thought: The Subtle Forces That Affect Your Appetite

May 31, 2016
Originally published on September 27, 2017 11:38 am

What do large tables, large breakfasts and large servers have in common? They all affect how much you eat. This week on Hidden Brain, we look at the hidden forces that drive our diets. First we hear from Adam Brumberg at Cornell University's Food and Brand Lab about how to make healthier choices more easily (hint: good habits, and pack your lunch!). Then, Senior (Svelte) Stopwatch Correspondent Daniel Pink returns for another round of Stopwatch Science to tell you about those tables, breakfasts and servers. If you don't like spoilers, stop reading and go listen to the episode!

Here are the studies:

  • You may have heard that smaller portions can help you eat fewer calories. That's true. But what about larger tables? Researchers Brennan Davis, Collin Payne and My Bui hypothesized that one of the ways smaller food units lead us to eat less is by playing with our perception. They tested this with pizza and found that while study participants tended to eat more small slices, they consumed fewer calories overall because it seemed like they were eating more. The researchers tried to distort people's perception even further by making the smaller slices seem bigger by putting them on a bigger table. What they found is that even hungry college students ate fewer calories of (free) pizza when it was chopped into tiny slices and put on a big table.

  • What about who's around that big table? That seems to matter, too. Researchers found both men and women order more food when they eat with women but choose smaller portions when they eat in the company of men.

  • They say breakfast is the most important meal of the day. Well, it may also be the most slimming. When researchers assigned two groups of overweight women to eat a limited number of calories each day, they found those who ate more at breakfast and less at dinner shed about twice as many pounds as the other group.

  • We often try to coax children into eating their vegetables by promising it helps them grow big and strong. Well, research suggests that's the wrong tack. Michal Maimaran and Ayelet Fishbach ran several experiments looking at how the way food is described affects how much of it children eat. They found kids ate fewer carrots and crackers when the foods were described as nutritious rather than tasty.

  • Having a heavier waiter may subtly prompt you to eat more. That's what Tim Döring and Brian Wansink found when they studied nearly 500 interactions between diners and servers. Diners ordered more items and more alcohol and were four times as likely to order dessert when waited on by a heavier server.

  • Here's some good news: Cheating on your diet may not be such a bad thing! Researchers found dieters who planned to relapse every once in a while lost just as much weight as those who didn't. What's more, those who treated themselves were happier with their diet, which could help them to stick to it longer.

The Hidden Brain Podcast is hosted by Shankar Vedantam and produced by Kara McGuirk-Alison, Maggie Penman and Max Nesterak. Special thanks this week to Daniel Shuhkin. To subscribe to our newsletter, click here. You can also follow us on Twitter @hiddenbrain, @karamcguirk, @maggiepenman and @maxnesterak, and listen for Hidden Brain stories every week on your local public radio station.

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This is HIDDEN BRAIN. I'm Shankar Vedantam. Millions of us try to lose weight every year. We go on diets, read books, buy pills off the Internet. Collectively, we spend billions of dollars trying to slim down. And the truth is, we might as well flush a lot of that money down the toilet.


UNIDENTIFIED MAN #1: All those workouts, challenges and temptations...


UNIDENTIFIED MAN #2: With thousands of diets out there, they've all chosen...


UNIDENTIFIED MAN #3: Jack was trying to teach me sugar equals pain. Yes, I was miserable.

VEDANTAM: As they say in the infomercials, there must be a better way. This week, we're going to talk about psychological tricks we can play on ourselves to help us eat better and to follow through on our best intentions.

ADAM BRUMBERG: My name is Adam Brumberg. I am the deputy director of the Cornell Food and Brand Lab at Cornell University.

VEDANTAM: Adam Brumberg and his colleagues research food psychology. And they find that many of our food choices aren't really conscious choices.

BRUMBERG: The majority of food decisions are based on habit or convenience. You know, habit being I did it yesterday. It worked out fine. I'm going to do it again. And convenience - well, I'm sitting at my desk, and there is, you know, a package of Ring Dings on the desk. And so I'm just going to eat that instead of going to find something that's healthier.

VEDANTAM: Once you understand these bad, unconscious patterns, you could stay on guard, use will power to fight them. But there's also a smarter way. You could turn the tables and get these unconscious habits to work for you.

BRUMBERG: Yeah, I mean, we like to say that the best diet is the one you don't know you're on. Our research shows you make about 200 food-related decisions a day, which is a lot.

VEDANTAM: By food decisions, Adam doesn't just mean whether you eat a salad or a sandwich. It's also how much salt do you put on your food? Do you have a slice of cake when your coworker celebrates a birthday? Do you reward yourself for going to the gym with a cookie? Here's one example of how you can turn the tables on your unconscious habits.

Adam and his colleagues find that volunteers in lab experiments make worse choices when they're stressed.

BRUMBERG: The stressed-out folks were more likely to buy a desert or to select a fried item as opposed to the people I asked to think of things they were grateful for, they were more likely to get salad or grilled chicken or, you know, whatever it was.

VEDANTAM: Once you understand how stress shapes mindless eating, you can set up a system when you're not stressed that allows you to take advantage of this tendency.

BRUMBERG: If you pack a lunch the night before, you're definitely going to put together something that's a lot more healthful than if you are, you know, doing it as you're running out of the house in the morning.

VEDANTAM: Now, Adam Brumberg says, when you're stressed out at work and mindlessly reaching for something to eat, your hand's going to come up with a carrot rather than a Ring Ding.

BRUMBERG: You have to work really hard to eat too many baby carrots.

VEDANTAM: We decided to devote this whole episode to ideas like this. Coming up in a moment, senior Stopwatch Science correspondent Dan Pink and I are going to trade psychological tricks that might help your actual waistline look like the one you want.

DANIEL PINK, BYLINE: Behavioral science has given us lots of tricks for eating less - smaller plates, smaller portions - but a new study this year in the Journal of the Association of Consumer Research offers another option, larger tables.

VEDANTAM: So pull up a chair and a big table and stay with us.


VEDANTAM: If you love listening to HIDDEN BRAIN, you're going to want to check out the new Code Switch podcast. Hosted by Gene Demby and Shereen Marisol Meraji, Code Switch is a podcast that helps us understand how race and identity shape our lives. This week, they tackle the subject of whiteness. What does it mean? And why is it important that we figure out how to talk about it? Find Code Switch on the NPR One app and at

This is HIDDEN BRAIN, I'm Shankar Vedantam. Summer is around the corner, which means beaches and swimsuits are around the corner, too. Today, with a view to getting myself into beach-ready shape, I've asked Daniel Pink to come in to trade psychological tricks on how to eat better. We're also going to look at some surprising factors that make us eat worse.

Dan, of course, is our senior Stopwatch Science correspondent, or actually I should say our svelte senior Stopwatch Science correspondent.

PINK: (Laughter).

VEDANTAM: Welcome, Dan.

PINK: Thank you, Shankar.

VEDANTAM: Now, I would say my body is beach ready on the radio. What about yours, Dan?

PINK: You know what? I don't really think in those terms. I tend to go out in public fully, if not heavily clothed.


VEDANTAM: All right. Now, as you know on Stopwatch Science, Dan and I give one another 60 seconds to summarize interesting social science research. As we approach the 60-second mark, our producers will bring up the music just like they do at The Oscars. Dan and I will each present three different pieces of social science research.

We'll also spend a little more time between the segments unpacking the signs and its implications. Our topic today is dieting and the many ways in which hidden and unconscious factors shape our diets. Dan, if you're ready, your first 60 seconds starts now.

PINK: Behavioral science has given us lots of tricks for eating less - smaller plates, smaller portions - but a new study this year in the Journal of the Association of Consumer Research offers another option, larger tables.


PINK: Yes. For these experiments, researchers got a bunch of pizzas and a bunch more college students. They found that students consumed the least amount of pizza when they were served small slices on a large table. It sounds weird, but there's a good explanation. When students saw the small slices on a tiny table, they quickly noticed just how measly those slices were.

So, of course, they grab more. But when those same small slices were on a big table, their attention shifted away from the smallness of the pizza slices and toward the largeness of the table. On a large table, the small slices seemed not so measly after all. So students didn't feel the need to pile as many on their plate and ended up consuming less pizza over all.

The lesson here, large tables may prevent large people.

VEDANTAM: (Laughter). All right, Dan. I have a question.

PINK: Yes.

VEDANTAM: So are the researchers saying that the fact that we see these pizza slices differently on small tables versus large tables, are they saying this is because of an optical illusion?

PINK: A little bit of an optical illusion. The way our vision works is that we don't see things in absolute terms. We see them in relative terms. So when you have small slices on a tiny table, you can actually see how small those slices are. But on a big table, everything looks about the same size because there's greater contrast.

Therefore, people on the big table will eat the small slices. They'll eat fewer of them and consume less pizza in total.

VEDANTAM: That makes sense.

PINK: So, Shankar, you and I are sitting here at a large table ourselves.

VEDANTAM: (Laughter).

PINK: So why don't you give us a small idea?

VEDANTAM: I'm going to give you a small portion of an idea, Dan.

PINK: (Laughter) A small slice.

VEDANTAM: It's going to fit in 60 seconds. It turns out it isn't just the size of your dining table that influences how much you eat. Your dining companions might make a difference, too. I did a story about this for NPR some time ago. Molly Allen-O'Donnell told me that when she was a graduate student at Indiana University of Pennsylvania, she sat down at a college cafeteria and looked at how much food people bought for lunch and dinner.

She noticed that when women sat with other women, they ordered an average 833 calories of food. When they sat with men, they ordered only 721 calories. So women ate more when they ate with women, and they ate less when they ate with men. Now, what about men? I hear you asking the question, Dan.

PINK: (Laughter).

VEDANTAM: What about men? When men sat with other men, they ordered 952 calories. But when they sat with women, they ordered 1,162 calories.

PINK: Oh, my God.

VEDANTAM: So another way to put this is both men and women ate more when they ate with women, and both men and women ate less when they ate with men. Now, I'm sure we're going to talk about why this might be the case, Dan.

But I want to take a moment to shout out to every overweight, married, heterosexual man who is listening. The next time your wife tells you to lose a few pounds, you might want to say, honey, it's your fault.


PINK: Oh, nice, nice. You know, I think it's interesting. The takeaway for me is that if you want to lose weight, eat with men.

VEDANTAM: I think that is one...

PINK: But why is that? Why...


PINK: Why do men eat so much around women?

VEDANTAM: I don't think the study conclusively answers that question, Dan. There was a related study that I saw by Kevin Kniffin at Cornell University. He and his colleagues found that men eat 93 percent more pizza and 86 percent more salad when eating with a woman compared to eating with a man. So it isn't just eating more unhealthy food. It's just eating more food in general.

Now, other studies have shown that heterosexual men in general tend to pursue more risky behaviors in the presence of women. Studies show that mixed sex groups, for example, make more risky financial decisions. So it's possible that men are acting out some kind of evolutionary script by eating more food and demonstrating they're capable of riskier behavior.

PINK: So they lose their inhibitions. They show, I'm a big risk-taker who can go out there and slay that saber-tooth tiger.

VEDANTAM: Exactly.

PINK: So, for my experience, back - many, many years ago, I would just be so psyched that a woman would be willing to eat with me...

VEDANTAM: (Laughter).

PINK: ...That I would probably lose my inhibitions - start gorging on pizza.

VEDANTAM: You know, it may be that men who are able to eat a lot of food may have signaled some kind of evolutionary fitness in our ancient past. Now, of course, when food is so plentiful today...

PINK: Right.

VEDANTAM: ...It might signal something else altogether.

PINK: A lack of fitness.


VEDANTAM: All right, let's see if you can signal to me that you can stick to your time, Dan.

PINK: (Laughter).

VEDANTAM: Your next 60 seconds starts right now.

PINK: You are what you eat. We've all heard that. But this next study shows you are also when you eat. Researchers at Tel Aviv University's medical school randomly assigned 93 overweight women into two groups. Both groups ate the same food, 1,400 calories a day, not very much, for 12 weeks. But one group consumed half the calories at breakfast.

The other group consumed half the calories at dinner. When the study was over, the big dinner group had lost an average of about seven pounds, not bad. But the big breakfast group, those who ate the same food, just earlier in the day, lost more than double that, an average of more than 17 pounds.

They also reduced their waistline more than the dinner group and even had greater drops in glucose, insulin and triglycerides, high levels of which can lead to metabolic problems. Again, same food, same calories, just a different schedule. The bottom line, in eating as in life, timing is everything.

VEDANTAM: So what I find interesting about the study, Dan, is that it contradicts a view that I think many people hold, which is that dieting is all just about calories in, calories out because what the study is suggesting is that it's not just about calories in, calories out. It's when you eat those calories that can make a huge difference.

PINK: Yeah, yeah. Our bodies are very, very complex systems. They don't work like simple machines. They're much more complex than that. And a lot of endocrinologists, a lot of physicians are trying to figure out exactly what that right mix is. But it turns out that questions of when can be just as important as questions of what. Now, here's a what question for you.

What do you got on your plate for your next study?

VEDANTAM: All right, this next study will be of interest to anyone who hangs around with small kids. What's one way you get youngsters to eat healthy food? You educate them about the health benefits of the food. But is this actually a good idea? New social science research suggests maybe not.

PINK: Uh-oh.

VEDANTAM: Michal Maimaran at Northwestern and Ayelet Fishbach at the University of Chicago find that children who are told that crackers are healthy infer that this means the crackers are not yummy, and they eat less of them. The researchers tried another experiment with carrots. They told preschoolers that eating carrots would help them become better readers.


VEDANTAM: Again, they find that creating this kind of instrumental goal causes the preschoolers to eat fewer carrots. Basically, the researchers think that when preschoolers are given one kind of association, crackers are healthy or carrots help you with reading, they unconsciously infer that alternate associations must be weaker, that the carrots and the crackers can't be tasty.

The moral of the story is if you want kids to eat certain kinds of food, sell the tastiness of the food, rather than the health benefits.

PINK: Wow. So sell the steak, not the sizzle, in other words.

VEDANTAM: Exactly.

PINK: Yeah, I also think another factor that could be at work here is that any child who hears an adult say that carrots will make you a better reader knows that is not an adult they could ever trust.


VEDANTAM: In other words, kids are just good lie detectors.

PINK: Yeah, exactly. Kids are good lie detectors, no matter what they eat. But it is interesting because we do - I mean, I remember when my kids were growing up. You know, you do want them to eat healthy. And so you're not sure how to persuade them to do it. And so, basically, what you're saying is that - push the good taste rather than the ancillary benefits.

VEDANTAM: Yeah, and I think when we think about many things in human behavior, Dan, I think we often assume that presenting the rational arguments to people is the best way to go.

PINK: Yeah.

VEDANTAM: And so if you're selling carrots, you sell the rational arguments that carrots are good for you. The rational arguments don't always work, and sometimes, they backfire.

PINK: Yeah, especially when it comes to eating.

VEDANTAM: All right, let's see if this rational argument has any benefits. Dan, if you're going to be done on time, you have to do your next segment on time. And your next 60 seconds starts right now.

PINK: Well, as we've discussed, all kinds of hidden forces affect how much we eat. But here's one I didn't expect - the weight of your waiter or waitress.

VEDANTAM: Oh, boy.

PINK: Tim Doering of the University of Gottingen in Germany and Cornell's Brian Wansink, one of the leading scholars of eating behavior, went to more than 50 restaurants in the U.S., from chains like Applebee's and Olive Garden to smaller, independent establishments. And they looked at interactions between diners and servers.

They found that customers were four times as likely to order dessert when they were served by wait staff with high body mass indexes than those with low BMIs.


PINK: People also ordered more alcohol from heavy servers than from slimmer ones. And the BMI of the diners themselves didn't matter at all. Now, this is what's called an observational study. It wasn't a controlled experiment. It doesn't mean that heavy waiters necessarily cause people to order the apple chimicheesecake.

Still, it shows, once again, how quiet factors, the setting we're in, the social cues around us, can influence what we do and even what we eat.

VEDANTAM: Here's a question for you, Dan. If I want to avoid this kind of bias, do you think it makes sense for me to decide what I'm going to order before the waiter actually shows up at my table?

PINK: Absolutely. There's a lot of evidence in eating and even in another kinds of behaviors that when - we make better decisions when we make them in advance rather than at that moment of truth when the triple brownie explosion melt is staring us in the face.

VEDANTAM: I like that because, of course, there's all this research showing that we make better decisions for our future selves. And so I'm going to tell you right now, Dan...

PINK: (Laughter).

VEDANTAM: ...I'm going to stick to my next 60-second deadline on my next Stopwatch Science segment.

PINK: OK, well, I'm going to set the timer. And it's going off right now.

VEDANTAM: All right, this is a study that makes me very happy. If you're on a diet, should you allow yourself to cheat? The rational answer is no. The HIDDEN BRAIN answer is yes. A study in the Journal of Consumer Psychology finds that when dieters are told they can have a day off each week from their diets, when they can eat whatever they want - this is a day of planned cheating - they did just as well when it came to losing weight as dieters who didn't give themselves any room to cheat.

Even better, the dieters who cheated reported being happier with their diets and maybe would stick to them much longer. The researchers have a wonderful academic euphemism to describe this kind of cheating. They call these hedonic deviations.

PINK: Nice.

VEDANTAM: The important thing to remember here is that the cheating has to be planned and deliberate. Most diets end with a crash. And when you crash, you feel like you failed. When you plan your hedonic deviations, it's not a crash. It's just a controlled landing before you take off again. It puts you in charge, makes you happier, might have long-term health benefits.

PINK: Yeah, that's quite fascinating. I actually think that some of it also has to do with autonomy, that when you're on a diet, you're very controlled. And so if you have this escape valve where you're in control, just for one day, that can probably make you feel better and probably boost adherence. I also love the idea of the hedonic deviation.

I think that I like to consider Stopwatch Science a hedonic deviation in the lives of American listeners.

VEDANTAM: (Laughter) I'll tell you what, I think I'm going to stick to my time better the next time, Dan, if occasionally, maybe once every two weeks, you give me two minutes...


VEDANTAM: ...To do a Stopwatch Science segment.

PINK: We can have a cheat day for Stopwatch Science.

VEDANTAM: All right, so there you have it. Buy a big table and cut your food into tiny pieces. Be mindful of your eating companions, or as Dan would put it, eat with men, not women.

PINK: (Laughter).

VEDANTAM: Eat a big breakfast, not a big dinner. Tell kids vegetables are tasty and not very healthy. Have a rule of thumb when you go to a restaurant - one drink, one entree. And if you're going on a diet, plan on indulging yourself once in a while. Dan Pink, thank you for joining me on Stopwatch Science.

PINK: Always a pleasure, Shankar.

VEDANTAM: The HIDDEN BRAIN podcast is produced by Kara McGuirk-Alison, Maggie Penman and Max Nesterak. Find more HIDDEN BRAIN on Facebook, Twitter and Instagram and hear my stories on your local public radio station. I'm Shankar Vedantam, and this is NPR.

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